export()
Here’s how to use export() function.
A .export()
Description:
Convert a sequence into a string.
Syntax:
A.export(x:F,…;s)
Note:
The function separates each selected fields x of records in table sequence/record sequence/sequence A with the user-defined separator and returns the result as a string. The name of the resulting field in the string is F. If x isn’t specified, then export all fields. Return a one-field string without a field name if A is a simple sequence; use separator when A’s members are sequences. A serial byte value is stored as an integer.
If parameters x:F are absent and if A is a sequence of record, then these records should be of same structure.
The function returns JSON strings when records or members of A is record, sequence or table sequence; and returns a hexadecimal string when records or members of A are serial byte keys.
Parameter:
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A |
A table sequence/record sequence/sequence to be exported |
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x |
Fields to be exported. If omitted, then export all fields of A |
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F |
Name of the resulting field in the string. If omitted, then use the original field name |
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s |
User-defined field separator. The default is tab |
Option:
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@t |
The column names will be written to the string as the first record |
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@c |
Use comma as the separator when the parameter s is absent, but the user-defined separator s should take priority when there are both s and @c option |
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@w |
Use Windows-style \r\n line break; by default, the line break is specified by the operating system. |
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@q |
Enclose the exported text field values and headers with quotation marks |
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@o |
Perform escaping according to the Excel rule, which treats two double quotation marks as one and does not escape the other characters Need to work with @q |
Return value:
String.
Example:
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A |
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1 |
=demo.query("select EID,NAME from EMPLOYEE") |
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2 |
=A1.export() |
Parameters x, F, and s are omitted |
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3 |
=A1.export(;"|") |
Specify the separator as "|" |
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4 |
=A1.export@t(EID:id,NAME:name;",") |
Specify to-be-exported fields and the separator; make column names the first record and write it at the beginning of the exported string |
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5 |
[1,23,34,45] |
A sequence |
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6 |
=A5.export() |
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7 |
=A1.export@c() |
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8 |
=A1.export@w() |
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9 |
=["12\r34","aa\nbb"] |
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10 |
=A9.export() |
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11 |
=A9.export@q() |
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12 |
<xml><row><DEPTID>1</DEPTID><DEPTNAME>sale</DEPTNAME><FATHER>12</FATHER></row><row><DEPTID>10</DEPTID><DEPTNAME>create</DEPTNAME><FATHER>12</FATHER></row></xml> |
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13 |
=xml(A12) |
Return a sequence of table sequences:
Expand members of the sequence as follows:
Then expand sub-members of the sequecne as follows:
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14 |
=A13.export() |
Return JSON strings
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15 |
=file("D://t4.txt").import@coq() |
Below is content of t4.txt:
A15’s result:
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16 |
=A15.export@coq() |
With @o option, two double quotation marks are treated as one
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Note:
Format of the string: Separate the records by space, and the fields by the user-defined separator. The default separator is tab.
Related function:
f .export( A , x : F ,…; s )
Description:
Write a sequence/table sequence/record sequence into a file.
Syntax:
f.export( A, x:F,…;s)
Note:
The function writes sequence/table sequence/record sequence A into file f in the form of text; it will auto-create an f, which is in the text format by default, if the file doesn’t exist (but the path can’t be auto-created).
If A is a table sequence or a record sequence, write all fields into the file if parameter x is absent. If the values of a to-be-exported field are referenced records, just write their primary key values into f. The unexportable fields in A can’t be written into f.
A must be sequence consisting of records of same data structure when it is a sequence. A one-field text file without field name will be written to file f when parameter x is absent.
By default, it writes data as JSON strings when members of A is sequence/record/table sequence. If A contains a serial byte field, the serial byte values will be written as hexadecimal strings. Use the original data type with the binary export.
Parameter:
|
f |
A file |
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A |
The table sequence/record sequence/sequence to be exported; use separators to export when members are sequences |
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x |
The field to be exported. If omitted, all the fields of A that can be textualized will be exported. The sign # is used to represent a field with a ordinal number |
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F |
Resulting field name. If omitted, then use the original field name |
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s |
The user-defined separator used in the text file, and the default separator is tab |
Option:
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@t |
Export field description, or the headers, as the first row of the file |
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@a |
Append. The appended records and the original records should be of the same structure, otherwise error will be reported. Ignore @t option if the there is data in the original file; overwrite the original file by default |
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@b |
Convert into binary file to speed up the processing and ignore @t options; won’t segment A if it is small enough, otherwise it will be segmented when being converted into the binary format; A is ordered by s when the latter is present and create a new segment whenever s is changed; s should be different for the newly-added data at append |
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@c |
Use comma as the separator when parameter s is absent, but the user-defined separator s should take priority when the parameter is present |
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@w |
Use Windows-style \r\n line break; by default, the line break is specified by the operating system; export a sequence of sequences as structured data where the first row is field names when @b option is also present |
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@q |
Enclose the exported text field values and headers with quotation marks |
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@o |
Perform escaping according to the Excel rule, which identifies two double quotation marks as one and does not escape the other characters |
Example:
Write a record sequence into a txt file.
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A |
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1 |
=demo.query("select * from DEPARTMENT") |
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2 |
=file("D:\\Department.txt").export(A1) |
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3 |
=file("D:\\Department.txt").export@t(A1) |
Use @t to export field headers in the first row as the title
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4 |
=file("D:\\Department2.txt").export(A1; "|") |
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5 |
=file("D:\\Department2.txt").export(A1;) |
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6 |
=file("D:\\Department2.txt").export@a(A1) |
Still the above example, append the contents from A1 to the contents of the file |
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7 |
=file("D:\\Department3.txt").export@b(A1) |
Export the file content in binary format |
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8 |
=file("D:\\Department4.txt").export@t(A1,DEPT:Dept1;"|") |
If not omitting x, then only export the specified field |
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9 |
=file("D:\\dept1.txt").export@ta(A1) |
Since dept1.txt does not exist, create it after the execution begins and then import the first row as the title |
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10 |
[a,s,d,f] |
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11 |
=file("D:\\myfile.txt").export(A10) |
myfile.txt is a one-field file without a field name |
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12 |
=file("D:\\Department6.txt").export@c(A1) |
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13 |
=demo.query("select * from EMPLOYEE order by GENDER") |
Sort by GENDER |
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14 |
=file("D:\\EMPLOYEE.btx").export@b(A13,EID,NAME,SURNAME,GENDER,SALARY;GENDER) |
Export the result returned by A13, which is by default ordered by GENDER to EMPLOYEE.btx |
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15 |
=file("D:\\EMPLOYEE.txt").export@w(A1) |
Use Windows-style \r\n line break |
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16 |
=demo.query("select * from DEPARTMENT").keys(MANAGER) |
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17 |
=A13.switch(DEPT,A16:DEPT) |
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18 |
=file("D:\\EMPLOYEE1.txt").export@t(A16) |
Values of DEPT field in A16 are referenced records; in this case the primary key of the table sequence need to be exported |
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19 |
=demo.query("select * from DEPARTMENT") |
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20 |
=file("D:\\Department7.txt").export(A19,#1) |
#1 represents the first column, so only that column of data is exported |
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21 |
=file("D:\\Dep1.txt").export@q(A19,#1) |
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22 |
f1,f2,f3 2,"dd""ff",3 |
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23 |
=A22.import@coq() |
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24 |
=file("D://t5.txt").export@coq(A23) |
With @o option, two double quotation marks in each string are treated as one; the exported content in t5.txt is as follows:
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Note:
Format of text file: Separate records by carriage return, and fields by the user-defined separator. The default separator is tab.
Related functions:
f .export( cs , x : F ,…; s )
Description:
Retrieve data from a cursor and write it to a text file.
Syntax:
f.export(cs,x:F,…;s)
Note:
The function writes data of cursor cs to the file object f as text. If the file does not exist, create it automatically (Note that the directory path cannot be created automatically).
Option:
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@t |
Export field description, or the headers, as the first row of the file. |
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@a |
Append. If omitted, then overwrite the original file. The option and @t are mutual exclusive. f and cs must be of the same structure, otherwise error will be reported. |
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@b |
Convert into binary file to speed up the processing. It ignores @t and does not support the parameter s. |
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@c |
Use comma as the separator when the parameter s is absent, but the user-defined separator s should take priority when there are both s and @c option. |
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@z |
Force the execution of @b and write the sequence to the binary file f in segment by segment. The sequence won’t be segmented without this option. With this option, the parameter s is the grouping expression ruling that sequence A is ordered by s, if the parameter exists, and perform the segmentation only when s changes. The binary file is used to export a large sequenece in segments with parallel processing, which will make sure records in each segment won’t be split. |
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@w |
Use Windows-style \r\n line break; by default the line break is specified by the operating system. |
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@q |
Enclose the exported text field values and headers with quotation marks |
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@o |
Use quotation marks as the escape character; need to work with @q. Without it the escape character is the Java-style slash (\) |
Parameter:
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f |
File object. |
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cs |
Cursor whose data to be exported. |
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x |
Fields to be exported. If omitted, then export all fields in the record sequence A that can be textualized. The sign # is used to represent a field with a ordinal number. |
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F |
Resulting field name. If omitted, then use the original field name. |
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s |
User-defined separator; the default is tab. |
Example:
Write the cursor data to the text file.
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A |
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1 |
=demo.cursor("select * from DEPARTMENT") |
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2 |
=file("D:\\Department1.txt").export(A1) |
Tab separator. |
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3 |
=demo.cursor("select * from DEPARTMENT") |
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4 |
=file("D:\\Department2.txt").export(A3;"/") |
Specify the separator “/”. |
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5 |
=demo.cursor("select * from DEPARTMENT") |
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6 |
=file("D:\\Department3.txt").export@t(A5) |
Write field names in the first row as the titles
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7 |
=demo.cursor("select * from DEPARTMENT") |
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8 |
=file("D:\\Department4.txt").export@t(A7,DEPT:Dept1,DEPT:Dept2;"|") |
If x is not omitted, then export the specified fields. |
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9 |
=demo.cursor("select * from DEPARTMENT") |
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10 |
=file("D:\\Department5.txt").export@t(A9,DEPT,MANAGER;"/") |
If F is omitted, then use the original field names. |
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11 |
=demo.cursor("select * from DEPARTMENT") |
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12 |
=file("D:\\Department5.txt").export@a(A11 DEPT,MANAGER;"/") |
Still the above examlple, append the contents of A12 to the contents of Department5.txt. |
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13 |
=demo.cursor("select * from DEPARTMENT") |
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14 |
=file("D:\\Department6.txt").export@b(A13) |
Export data as the binary file to get a higher speed. |
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15 |
=demo.cursor("select * from DEPARTMENT") |
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16 |
=file("D:\\Departmen7.txt").export@c(A15) |
Use comma as the separator |
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17 |
=demo.cursor("select * from EMPLOYEE order by GENDER") |
Sort by GENDER. |
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18 |
=file("D:\\EMPLOYEE1.btx").export@z(A17,EID,NAME,SURNAME,GENDER,SALARY;GENDER) |
Export a segmented binary homo-name files grouped by GENDER to EMPLOYEE.btx |
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19 |
=demo.cursor("select * from EMPLOYEE order by GENDER") |
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20 |
=file("D:\\EMPLOYEE2.txt").export@w(A19) |
Use Windows-style \r\n line break. |
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21 |
=demo.cursor("select * from DEPARTMENT") |
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22 |
=file("D:\\Department8.txt").export(A21,#1) |
#1 represents the first column, so only that column in the cursor is exported |
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23 |
=file("D:\\Dep1.txt").export@q(A21) |
Both exported field values and headers in the text file are quoted |
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24 |
=["12\r34","aa\nbb"].cursor() |
Above is the content of the cursor |
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25 |
=file("D:\\Dep2.txt").export@q(A24) |
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26 |
=file("D:\\Dep3.txt").export@qo(A24) |
Use double quotations as the escape character |
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Related function: